The Design Institute of Australia (DIA) is Australia's peak membership body for professional designers and design businesses.

Membership of the DIA indicates a designer’s status as a qualified, experienced, ethical practicing professional. It also provides designers and design businesses with support, networking, services and information to improve professional and industry practice.

Since its formation in 1947 the DIA has been actively improving the community recognition and status of professional designers. It is a professional body for designers, founded by the design professions, and run and funded by designers.

The DIA promotes the value of professional design and designers to industry, business, government and the community through its National Council and State Branches. The DIA champions the importance of design in building the commercial and cultural wealth of Australia.

On behalf of its members the DIA is a member of major international design organisations including IFI (International Federation of Interior Architects and Designers) and APSDA (Asia Pacific Space Designers Association).